The Life, Times, and Scientific Labours of the Second Marquis of Worcester / To which is added a reprint of his Century of Inventions, 1663, with a Commentary thereon.

by Henry Dircks

Here we have “condensation” a second time adverted to, while the whole experiment proves the folly of attributing to Savery a similar result as a novelty leading for the first time to a knowledge of the property of “condensation,” to the disparagement of the Marquis and his predecessors, assuming their total ignorance of what is here so clearly and graphically described.

Again, Van Etten in the fifth section of Problem LXXXV. treats—“Of a fine fountaine which spouts water very high, and with great violence by turning of a cock.” page 193. “Let there be a vessel made close in all its parts, in the middle of which let a pipe open neare the bottome; and then with a squirt squirt in the water (stopped above by the cock or faucet) with as great violence as possible you can, and turne the cock immediately. Now there being an indifferent quantity of water and aire in the vessel, the water keeps itself in the bottom, and the aire which was greatly pressed, seeks for more place, that turning the cock the water issueth forth at the pipe, and flyes very high, and that especially if the vessell be a little heated.” The concluding sentence would no doubt afford a mind like that of the Marquis of Worcester’s abundant matter for experimental trial, if ever consulted by him, either in the original, or in the translation of 1633.

The following extract from Van Etten’s 83rd Problem, “Of Cannons or great Artillery,” affords strong presumptive evidence (taken along with other extracts) of the Marquis’s acquaintance with the work. The Problem is divided into two parts, of which the first alone need be noticed, namely,—“How to charge a cannon without powder.” It is observed—“This may be done with aire and water, only having thrown cold water into the cannon, which might be squirted forceably in by the closure of the mouth of the piece, that so by this pressure the aire might more condense, then having a round piece of wood very just, and oiled well for the better to slide, and thrust the bullet when it shall be time. This piece of wood may be held fast with some pole, for feare it be not thrust out before his time: then let fire be made about the trunnion or hinder part of the piece to heat the aire and water, and then when one would shoot it let the pole be quickly loosened, for then the aire searching a greater place, and having way now offered, will thrust out the wood and the bullet very quick: the experiment which we have in long trunkes [tubes] shooting out pellats with aire only, sheweth the verity of this Probleme.” (page 173.)

The words italicised are a complete description of the Marquis’s experiment, although made with a widely different object, but both afford evidence of the force obtainable from a small quantity of heated water, the one in an imperfectly closed, the other in a well closed cannon. It is remarkable how near this experiment comes to the steam-engine cylinder, piston, and safety valve; and we can scarcely believe that such applications would escape the Marquis’s observation, when repeated and varied as was his customary course in pursuing his own inquiries.

We have thus, from 1615 to 1653, shown, what sources were open to afford suggestions to the Marquis of Worcester’s wakeful and watchful mind, alive and on the alert to seize on every hint promising some enlarged and useful application. We come next to that part of his own statement, where he says: “so that having found a way to make my vessels, so that they are strengthened by the force within them, and the one to fill after the other, &c.” “Vessels” may here apply to cisterns, receivers, boilers, &c., in short whatever appliances were used. But it is usually supposed to mean the boiler only, and hence the difficulty to understand how its safety should increase with the increased internal expansive force of the steam. But allowance must be made for the general vagueness throughout the “Century,” and we must bear in mind that its language was not arranged to inform the public in respect to construction, but, as its author explicitly states, the several inventions are “set down in such a way as may sufficiently instruct me to put any of them in practice.” Now there is good ground for believing that the Marquis had a special meaning for the word “force,” as here applied, a word then used indifferently in its ordinary and in a technical sense, in the same sentence. This is particularly worth illustrating; firstly, because it shows a probability that the Marquis had, before 1655, designed some kind of safety-valve; and secondly, to remove the common supposition of the foregoing invention being utterly paradoxical.

It has already been stated, that there is sufficient evidence to prove, that John Bate’s “Mysteries of Nature and Art,” had attracted the especial notice of the Marquis. He would be about 33 years of age on its first publication, and he wrote his Century about 20 years after its appearance, we may, therefore, readily see how likely it would be for him to adopt even its very style and language. John Bate says, at page 11:—

“A forcer is a plug of wood exactly turned and leathered about; the end that goeth into the barrel, is semicircularly concave; p. 57. Forces may be made to move either horizontally or perpendicularly, according unto the convenience of the work, or the invention of the artist and engineer; p. 59. (Describing ‘the water mill or engine near the north end of London Bridge.’) These two barrels must be bound fast unto two posts of the frame, with two strong iron bands, as T T; unto each of these must be fitted a force well leathered, and in the tops of the forces must be set two pieces of wood.”

Then again, at page 66:—“K K, L L, the barrels of the forces, which force the water;” p. 67. “E, a barrel of brass or wood fastened in the well, K, a force fitted into it.” Again, “the force must be very heavy;” p. 71. “B, a barrel of iron or brass, fastened in the midst of the cistern, with a force fitted unto it;” p. 72. “The force is linked, and it is noted with the letter D,” (in the engraving.) Again, “F, the barrel of the force, fastened within two or three inches of the bottom of the cistern;” p. 73, “C, a force, D, the forces barrel.” Again, “the force draweth the water out of the cistern B, into the barrel D;” p. 74, “another strong iron bar as I I, unto each end whereof must be linked a force; K K, the two barrels of the aforesaid forces.”

In the 21st volume of Philosophical Transactions, published in 1700, there is a description, with an engraving,[M] being, “An account of Mr. Thomas Savery’s engine for raising water by the help of fire.” It states that Mr. Savery, on the 14th of June, 1699:—“Entertained the Royal Society with shewing a model of his Engine for raising water by the help of fire, which he set to work before them; the experiment succeeded according to expectation, and to their satisfaction. The Engine may be understood by the draughts of it, where Fig. 1 is the front of the Engine for raising water by fire; and Fig. 2, the side prospect of the Engine.